Why do my MATLAB plots always begin from zero?

10 次查看（过去 30 天）
Michael
Michael 2014-10-30
回答： Image Analyst 2014-10-31
suppose I have the following equation y = cos(n)
to make the discrete plot
figure
subplot(2,2,1);
n = linespace(-10,10,20);
y = cos(n);
stem(y)
xlabel('blah blah blah')
ylabel('y[n]')
title('blah')
grid on
When I save the above code in a MATLAB scipt and run it in MATLAB, my graphs always begin from zero, even when I explicitly specify in the the beginning endpoint be negative linspace(-10,10,50)
Why does it do this?

请先登录，再回答此问题。

回答（2 个）

Star Strider
Star Strider 2014-10-30
The begin and end wherever you tell them to.
Change your stem call to:
stem(n,y)
and see if that improves your result.
Image Analyst
Image Analyst 2014-10-31
Becuse you're not passing in the "X" values, which you call n. Also, did you know that you can call xlim() to have the axes start and stop wherever you want? Otherwise it tried to pick nice "round" numbers rather than weird fractional numbers. Try this:
n = linspace(-10,10,20);
y = cos(n);
stem(n, y, 'LineWidth', 3)
xlabel('n')
ylabel('cos(n)')
title('Stem of cos()')
grid on;
xlim([min(n), max(n)]);

类别

在 Help Center 和 File Exchange 中查找有关 Annotations 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by